M12 GTO Gearbox
Discussion
Hi all,
I was wondering, does anyone know if there are any advantages to the 5-speed transmission in a GTO-3 vs the 6-speed version in the R? I have read somewhere that the 5-speed is stronger but most places say the 6-speed is more durable.
Is this all down to the differentials? Or can the actual gears themselves break down more on one vs the other?
The 5-speed has lower ratios for 1st and 2nd, so I'm thinking it would actually be faster to 60 with the 5-speed?
The 6-speed has lower ratios for 3rd 4th and 5th, so would be quicker from 60 onwards I presume. Would you even be able to detect any difference in the speed do you think?
If I was to be driving a GTO mostly on the road, with the occasional trip to the track, which diff would be the best, open or LSD? I have heard that the open diff is better on the road and easier to drive. Is there any truth to this or is having the LSD better in every regard?
Any advice would be greatly appreciated!
Thanks in advance,
Andrew.
I was wondering, does anyone know if there are any advantages to the 5-speed transmission in a GTO-3 vs the 6-speed version in the R? I have read somewhere that the 5-speed is stronger but most places say the 6-speed is more durable.
Is this all down to the differentials? Or can the actual gears themselves break down more on one vs the other?
The 5-speed has lower ratios for 1st and 2nd, so I'm thinking it would actually be faster to 60 with the 5-speed?
The 6-speed has lower ratios for 3rd 4th and 5th, so would be quicker from 60 onwards I presume. Would you even be able to detect any difference in the speed do you think?
If I was to be driving a GTO mostly on the road, with the occasional trip to the track, which diff would be the best, open or LSD? I have heard that the open diff is better on the road and easier to drive. Is there any truth to this or is having the LSD better in every regard?
Any advice would be greatly appreciated!
Thanks in advance,
Andrew.
I've not driven a 5 speed but i imagine any difference to 60 is going to be so miniscule that other variables in a given 0-60 run will have a bigger effect (traction, reaction time etc).
A few owners have on here have had both, I seem to remember Joust mentioning the longer 3rd gear gives more of an impression of surging forward - You do swap cogs quickly in a 3R.
LSD is more reliable than open diff, they tend to go bang. Its always on the must haves list :
Fuel Pump Mod, LSD, Track day sump etc.
A few owners have on here have had both, I seem to remember Joust mentioning the longer 3rd gear gives more of an impression of surging forward - You do swap cogs quickly in a 3R.
LSD is more reliable than open diff, they tend to go bang. Its always on the must haves list :
Fuel Pump Mod, LSD, Track day sump etc.
Wait for it to break or enjoy breaking it. Its expensive to fix though.
My advice is buy a lowish milage 40k Mondeo box (less stressed than in a Noble).
Send it to gearbox Mand fit upgrading and have LSD fitted. The hopefully there is time between this expense and when the box breaks so it's not one big outlay. I got Mondeo box for £200 and gearbox man said it was in great condition with 42k on it.
My advice is buy a lowish milage 40k Mondeo box (less stressed than in a Noble).
Send it to gearbox Mand fit upgrading and have LSD fitted. The hopefully there is time between this expense and when the box breaks so it's not one big outlay. I got Mondeo box for £200 and gearbox man said it was in great condition with 42k on it.
I was just looking on another site and it stated that the 3R had a LSD fitted as standard. It also states that some 3Rs were the 5-speed. Does this mean that this 3R I have found could have a 5-speed with a LSD or is this impossible?
If and when the Open diff were to break, do you have to get a whole new gearbox? And would it have to be a 6-speed?
If and when the Open diff were to break, do you have to get a whole new gearbox? And would it have to be a 6-speed?
Well, it is certainly possible, altho that would require a whole new clamshell would it not? It actually has M400 lights. Is it possible to modify a non R clamshell to take the M400 lights? It has 3R badges behind the front wheels but I guess this is not conclusive either. It does also appear to have an engine start button, am I right in thinking the standard car does not have this either? It also has a leather interior.
Is there any way to inspect the car to make absolutely sure which it is? Is it possible to determine if it has the LSD fitted? You said they did originally have the 5-speed gearbox with the 6 as an option, but did the 5-speed come with a LSD? I would really like to make 100% sure if it has the LSD before I make an offer on the car.
Thanks,
Andrew.
Is there any way to inspect the car to make absolutely sure which it is? Is it possible to determine if it has the LSD fitted? You said they did originally have the 5-speed gearbox with the 6 as an option, but did the 5-speed come with a LSD? I would really like to make 100% sure if it has the LSD before I make an offer on the car.
Thanks,
Andrew.
Just to answer your questions below,
M400 lights? They have the same as 3r
Yes you can cut the front clam to fit 3r lights, many have done this.
Things like start button, leather were options on a GTO3 - so thats not a conclusive way to say its an R for certain.
If they can tell you the chassis number it will have R near the end if it is actually a 3R
From what i know of the 5 speed didnt come with a LSD, just open diff. If you are buying from a garage that knows nobles, Keridges, Bespoke, Jetstream etc they will be able to tell you this. If its private, it might be known on here - if its been looked after well there should be receipts.
M400 lights? They have the same as 3r
Yes you can cut the front clam to fit 3r lights, many have done this.
Things like start button, leather were options on a GTO3 - so thats not a conclusive way to say its an R for certain.
If they can tell you the chassis number it will have R near the end if it is actually a 3R
From what i know of the 5 speed didnt come with a LSD, just open diff. If you are buying from a garage that knows nobles, Keridges, Bespoke, Jetstream etc they will be able to tell you this. If its private, it might be known on here - if its been looked after well there should be receipts.
28Ace82 said:
Well, it is certainly possible, altho that would require a whole new clamshell would it not? It actually has M400 lights. Is it possible to modify a non R clamshell to take the M400 lights? It has 3R badges behind the front wheels but I guess this is not conclusive either. It does also appear to have an engine start button, am I right in thinking the standard car does not have this either? It also has a leather interior.
Is there any way to inspect the car to make absolutely sure which it is? Is it possible to determine if it has the LSD fitted? You said they did originally have the 5-speed gearbox with the 6 as an option, but did the 5-speed come with a LSD? I would really like to make 100% sure if it has the LSD before I make an offer on the car.
Thanks,
Andrew.
Is there any way to inspect the car to make absolutely sure which it is? Is it possible to determine if it has the LSD fitted? You said they did originally have the 5-speed gearbox with the 6 as an option, but did the 5-speed come with a LSD? I would really like to make 100% sure if it has the LSD before I make an offer on the car.
Thanks,
Andrew.
It is a private sale, altho he has asked a garage to advertise it for him too. They could not tell me about the diff.
I have found today a motorsport place that sell a 5-speed quaife ATB LSD as well as the 6-speed model so it would appear it is definitely possible to have the 5-speed with the LSD but this is not at all conclusive either!
I've asked him for the chassis number so I will at least be able to ascertain that it is 100% a 3R. Do you know when the first 3Rs were produced? This car was registered on 25th June 2003.
Thanks for the advice!
Andrew.
I have found today a motorsport place that sell a 5-speed quaife ATB LSD as well as the 6-speed model so it would appear it is definitely possible to have the 5-speed with the LSD but this is not at all conclusive either!
I've asked him for the chassis number so I will at least be able to ascertain that it is 100% a 3R. Do you know when the first 3Rs were produced? This car was registered on 25th June 2003.
Thanks for the advice!
Andrew.
If the diff was to go, could you just replace the gearbox with another 5-speed? I presume that would be quite cheap.
Is there nothing special about the 5-speed open diff box? Is it exactly the same as what was in a mondeo? The 6-speed is the same? As in, the ST220 came with the 6-speed with quaife LSD and they just fitted the whole unit. No modifications required to the internals on either box?
Is there nothing special about the 5-speed open diff box? Is it exactly the same as what was in a mondeo? The 6-speed is the same? As in, the ST220 came with the 6-speed with quaife LSD and they just fitted the whole unit. No modifications required to the internals on either box?
Hiya, I have a 3R, it's an early one and has the 5 speed box. It does have the Quaife diff, this was fitted afterwards by Jetstream. I was worried about the 5 speed box (it was broken when I bought it) and planned to change for a 6 speed box, the ratios are good though and the Gearboxman (Bernie) very helpful. It's very likely you are looking at an early 3R like mine with the 5 speed box but with the standard open diff. As everyone says, use it, enjoy it and plan to replace it when it goes, the change to a 6 speed is a lot of work though, installing a quaife in a rebuilt 5 speed is not too bad. Cheers, Steve
Noble modified the mondeo box, so you cant just pick it up and put it in. LSD is about £600, its the labour to fit is where the cost is and while the engines out you might as well do the other bits such as clutch.
My GTO3 is a 2003. So i would say its an early 3r with open diff 5 speed. Just budget for the work in future or buy another with one in place.
My GTO3 is a 2003. So i would say its an early 3r with open diff 5 speed. Just budget for the work in future or buy another with one in place.
28Ace82 said:
If the diff was to go, could you just replace the gearbox with another 5-speed? I presume that would be quite cheap.
Is there nothing special about the 5-speed open diff box? Is it exactly the same as what was in a mondeo? The 6-speed is the same? As in, the ST220 came with the 6-speed with quaife LSD and they just fitted the whole unit. No modifications required to the internals on either box?
Is there nothing special about the 5-speed open diff box? Is it exactly the same as what was in a mondeo? The 6-speed is the same? As in, the ST220 came with the 6-speed with quaife LSD and they just fitted the whole unit. No modifications required to the internals on either box?
Thanks for the info Steve, I think that is deffo the best idea. I like the idea of the 5 ratios instead of 6 so that seems to be by far the best option. I'm imagining surfing the wave of torque in 3rd and never changing to 4th..... 
I presume nobody would ever replace the open diff with another one the same, even if they were cheaper, cos it will just fail again. I can't even find any for sale anyway, for this reason I'm sure.
One more question, does yours have the radiator fan shroud upgrade and if so, was it fitted at the factory or did you have that done yourself? The car I am looking at has the fans attached directly to the radiator, which I had thought was only on the GTOs but I am guessing it was still used on early 3Rs. Peter at SBITS also tells me this car has the older power steering reservoir, does yours have that too?
Cheers,
Andrew.
I presume nobody would ever replace the open diff with another one the same, even if they were cheaper, cos it will just fail again. I can't even find any for sale anyway, for this reason I'm sure.One more question, does yours have the radiator fan shroud upgrade and if so, was it fitted at the factory or did you have that done yourself? The car I am looking at has the fans attached directly to the radiator, which I had thought was only on the GTOs but I am guessing it was still used on early 3Rs. Peter at SBITS also tells me this car has the older power steering reservoir, does yours have that too?
Cheers,
Andrew.
stevegto3 said:
Are u sure they modded it Steve. I brought a Mondeo box (correct part number as there are a few different types). Sent it to gearbox man for internal upgrades and it fitted right in with no mods?As far as I'm aware, no 5 spd came std with a LSD. All were fitted later.
stevegto3 said:
I have a GTO3, it has all except the LSD, so has open diff. I plan to enjoy it and just deal with it when it happens.
Im just budgeting for when it eventally goes, as its an engine out job, so will probbaly have the box upgraded at the same time, plus clutch. Approx £2500-£3500.
Steve
I replaced my open diff in mine when it went by cutting the cross braceIm just budgeting for when it eventally goes, as its an engine out job, so will probbaly have the box upgraded at the same time, plus clutch. Approx £2500-£3500.
Steve
and fabricating sleaves and solid inserts so I can get to gearbox again which iv done.
Bit of a pig of a job to get gearbox out even with cutting cross brace but I did it
in a day without being in the trade.
Think lsd was about £600 with parts n labour
Then spent about two days of n on putting it all back.
So you can save money if you get your hands dirty.
You wouldnt want to replace it with the same. Bondy is a good resource to this as he has done this.
Not sure about the shroud, mine went back to mole valley to have TDS and ECU swapped to MBE soon after purchase so that might have been done, im sure mine still has fans installed to the rad anyway. Do they not mean the intercooler shroud?
Bondy - i thought the internals were uprated from standard to cope with the extra power at factory? I might be wrong, not sure.
Not sure about the shroud, mine went back to mole valley to have TDS and ECU swapped to MBE soon after purchase so that might have been done, im sure mine still has fans installed to the rad anyway. Do they not mean the intercooler shroud?
Bondy - i thought the internals were uprated from standard to cope with the extra power at factory? I might be wrong, not sure.
28Ace82 said:
Thanks for the info Steve, I think that is deffo the best idea. I like the idea of the 5 ratios instead of 6 so that seems to be by far the best option. I'm imagining surfing the wave of torque in 3rd and never changing to 4th..... I presume nobody would ever replace the open diff with another one the same, even if they were cheaper, cos it will just fail again. I can't even find any for sale anyway, for this reason I'm sure.
One more question, does yours have the radiator fan shroud upgrade and if so, was it fitted at the factory or did you have that done yourself? The car I am looking at has the fans attached directly to the radiator, which I had thought was only on the GTOs but I am guessing it was still used on early 3Rs. Peter at SBITS also tells me this car has the older power steering reservoir, does yours have that too?
Cheers,
Andrew.
I presume nobody would ever replace the open diff with another one the same, even if they were cheaper, cos it will just fail again. I can't even find any for sale anyway, for this reason I'm sure.One more question, does yours have the radiator fan shroud upgrade and if so, was it fitted at the factory or did you have that done yourself? The car I am looking at has the fans attached directly to the radiator, which I had thought was only on the GTOs but I am guessing it was still used on early 3Rs. Peter at SBITS also tells me this car has the older power steering reservoir, does yours have that too?
Cheers,
Andrew.
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